The discoloration principle of photochromic lenses
The fine grains of silver halide and copper oxide were melted into the glass melt of the lens blank material to produce the lens. When the lens is in the ultraviolet environment, the silver halide molecules will undergo a chemical reaction due to the ultraviolet radiation and decompose into silver ion particles and halogens. Because the silver particles are dark and absorb visible light, the lens gets darker. When the ultraviolet light is weakened or isolated, silver ions and halogens are recombined under the action of catalyst copper oxide to form silver halide, so the color of the lens gradually becomes lighter and transparent again. The discoloration mechanism of the resin lens is similar to that of the glass lens.
Choose high-quality lenses.
As resin lens technology becomes more and more mature now, resin lens has gradually become popular, so the use of resin lens is the trend. Now resin coated lenses are very popular now. There are anti-reflection films and hard films (anti-wear films) anti-UV films. Anti-reflection film can improve the transmittance of light, making people see more clearly, at the same time, because it can reduce the reflection, the lens is more beautiful in appearance. Hard coating films can effectively protect the lens surface from wear and tear and can resist the damage of hard objects, to prolong the life of the lens. UV-resistant films block the harmful ultraviolet rays of sunlight. For example, the UV400 lens is good for engineers who work outdoors for a long time.
Are titanium glasses frames worth it?
In order to exert the flexibility of the material, the β titanium frame is designed to be mostly fine and delicate, and the style is limited by this. So the price of a pure titanium glasses frame is more expensive than the beta titanium frame, of course, the comfort is higher. Beta titanium has better strength, fatigue resistance, and environmental corrosion resistance than pure titanium and other titanium alloys. It has good shape plasticity and can be made into wire and sheet, which is lighter.
Because the texture of pure titanium frame is better, so it is more expensive than other frames, at least should the price reach more than 20 dollars, if the frame is only a few dozen dollars, then it must be fake and inferior. The most important thing to avoid buying fake products is to choose brands. For example, Seiko and other well-known brands rarely have fake and inferior products, so that consumers can be more assured to buy.
Orthokeratology lens
Orthokeratology lenses appeared in the United States in the 1960s and became mature in the 1980s. In 1996, Taiwan first imported the product, and it entered mainland China the following year. It is called OK lens for short because of its pronunciation. After OK lens entered China, it was immediately found by businessmen. A lot of institutions and individuals who do not have the relevant qualifications have flooded into the operation of the OK lens. On July 5, 2001, the State Food and Drug Administration formulated the Regulations on the Supervision and Administration of the Operation, Inspection and Matching of Orthokeratology Lens, which regulated the operating institutions and testing and matching institutions of Orthokeratology lenses. But in China, the rule did not change the course of events.
Different Types of Progressive Lenses
The ground-view progressive lenses are designed for people who enjoy the outdoors. These lenses are supposed to provide a natural feel to your vision and reduce lens distortion. Ground-view progressive lenses allow better vision through the sides and bottom of the lens, so they give you improved vision when driving, using computers and looking downwards.
The standard progressive lenses are exactly what they sound like. They offer a wide reading area and have a longer drop between prescriptions and require a larger frame. However, they are less specialized than other lenses.
Blue light in natural light
Blue light is not the unique light emitted by electronic products, but the visible light that exists in natural light, usually with a wavelength of about 400-500nm. The blue light in the entire waveband can be subdivided into two parts. One part will cause optical damage to the retina of the eye and accelerate the oxidative senescence of cells in the macular area of the retina. Usually, the wavelength of this part of blue light is between 415-450nm, and its damage to the eyes is gradually accumulated and formed. There is also a part of blue light that is beneficial to our human body, that is, blue light with a wavelength of about 480nm. It can adjust biological rhythms and is helpful for sleep, mood, and memory. In addition, experiments have confirmed that daily outdoor activities in the sun can effectively prevent the occurrence of myopia, and short-wavelength blue light may play an important role.
Can You Wear Blue Light Glasses All Day?
Can I wear blue light glasses all the time? You may also have the query. To answer this question, you need to know one thing that the blue light isn’t inherently bad for you but an excess of blue light will lead to some negative effects.
The natural sources of blue light from the outdoors and from sunlight is good for you. In addition, since the HEV wavelengths is important to our moods and sleep rhythms, blue light can be used to treat seasonal effective disorder and other mental health issues.
The blue light glasses is used to guard against artificial source of blue light that deliver excessive amounts of this wavelength to your retinas. So, if you need to stay daytime hours under artificial light or working at a computer, you had better wear your blue light blocking glasses during the day.
So, is it bad to wear blue light glasses all day? The answer is negative.
